Did you by chance save the MPQ file as ".mpq" instead of ".MPQ"? it is case sensitive. Other then that, if you changed the spells as directed as above, it should work perfectly fine.
Also reffering back to the trinket trouble i had, I didnt look up the item ID itself, i looked up the item and clicked on the effect on wowdb.com (this should bring you to the buff you want to change). It was 1 number off for some reason. instead of a 4 at the end it was a 3